VCSA Convergence: Failed to Get RPMs

One of my vSphere 6.7 U3 environments I am managing was still using external Platform Services Controller (PSC) from times when it was the prescribed architecture. That is no longer the case so to simplify my management I wanted to get rid of the external PSC via so called Convergence to embedded PSC.

Unfortunately although there is a very nice UI to do this it never worked for me. And I did try multiple times. The error I always ended up was:

Failed to get RPMs.

The /var/log/vmware/converge/converge.log log did not show any error, but what was peculiar there was this entry referring to download of VCSA 6.5.0 files?!

These are obviously not correct for my 6.7 U3 VCSA appliance. This VMware Communities thread finally pushed me in the right direction.

Here are the steps how to resolve this:

Delete content of /root/vema directory on VCSA

Download correct VCSA ISO installation media corresponding to the version of your VC. In my case it was the full 4 GB VMware-VCSA-all-6.7.0-14836122.iso. The patch media VMware-vCenter-Server-Appliance-6.7.0.41000-14836122-patch-FP.iso cca 2 GB large did not work.